Landfill Status

Landfill Maximum Temperature at Depth

The landfill is experiencing an extensive exothermic reaction, known as a subsurface elevated temperature (SET) event, which continues to expand. Normally landfill gas well temperatures are 130 degrees F or less.  At the Chiquita Canyon landfill, gas well temperatures are substantially higher, in the waste mass. This map shows the highest temperatures at depth at temperature monitoring probes across the landfill. It shows that these temperatures are elevated across the landfill from the western to the eastern edge. These temperatures have been increasing over time as shown by the greater number of red and brown colored wells over time.

The map below is currently showing temperatures every three months. Click on the "Play" Button on the bottom to see the temperature over time from January 2024 to August 2026.

Gas Quality

One indicator of the extent of the reaction at Chiquita Canyon Landfill is the ratio of methane to carbon dioxide in landfill gas. Normally, bacterial degradation of the waste over time causes methane and carbon dioxide to be released in relatively equal levels in landfill gas. However, the reaction at Chiquita Canyon Landfill kills bacteria that generate methane. 

The map below shows depressed methane levels measured from individual wells in magenta and orange, which exist not only in the northeast corner of the landfill where the reaction has been concentrated, but also across the landfill. The video below shows the conditions over time so that the gas quality over time is visible.

Leachate Generation

Another indicator of the reaction is the amount of leachate that is generated by the landfill. As the reaction progresses, it heats the landfill, releasing liquid from the moist waste mass.  Leachate generation increases as the reaction impacts the waste, and will eventually decrease as the liquids are released and removed from the waste mass. Leachate generation rates are currently increasing, indicating that the reaction is expanding and continuing to release liquids from newly impacted waste mass.  

Public Nuisance

The most significant impact from the reaction is the exposure to noxious, odorous gases released by the Chiquita Canyon Landfill that impact surrounding neighborhoods. The table below shows the number of complaints from surrounding communities about odors from the landfill, and the number of notices of violation issued by South Coast AQMD - to the landfill for public nuisance. Each violation represents a confirmed complaint, in which the AQMD has received complaints from at least six individuals in one day, and confirmed the odor is present and coming from the landfill.
Updates, information and resources from the Response Multi-Agency Coordination group, responsible for immediate mitigation plans related to leachate at Chiquita Canyon Landfill.